番荔枝中一个SWEET家族基因的克隆与表达分析

以番荔枝不同组织样品为材料,通过基因文库筛选,利用RT-PCR技术克隆出1个1227 bp的基因,命名为AT-SWEET16-1,该基因编码408个氨基酸,该氨基酸序列在N端以α螺旋形成THB结构域。生物信息学分析结果表明,该蛋白分子量为44.8 kDa,等电点为8.87。进化分析结果发现其与海枣（Phoenix dactylifera）相类聚。qRT-PCR分析结果表明,该基因在植株的根、茎、嫩叶、老叶、花蕾、花苞、幼果、成熟果中均有表达,AT-SWEET16-1基因在不同组织中的表达量依次是：成熟果>茎>根>花蕾>幼果>老叶>嫩叶;该基因在不同果实发育阶段中的表达情况为：在果实不同发育阶段,果柄中的表达量最高,果肉、果皮中则相对较低,种子中最低;但果实成熟期该基因在果柄、果肉中的表达量最高。原位杂交实验观察发现,基因表达位置为果柄韧皮部、果肉细胞膜间,结合基因表达分析结果,预示该基因在植株糖分积累与转运等方面起到一定的作用。

Cloning and Expression Analysis of a SWEET Family Gene from Annona squamosa L.

The fruit at different stages of Annona squamosa L. was used as the experimental material. A gene named AT-SWEET16-1 with 1227 bp was cloned by RT-PCR, which encoding 408 amino acids. The amino acid sequence had a α-helix THB domain at the N-terminal. Bioinformatics analysis showed that the molecular weight of the protein was 44.8 kDa, and the isoelectric point was 8.87. Evolutionary analysis showed that it was associated with Phoenix dactylifera). qRT-PCR analysis showed that the gene was expressed in roots, stems, tender leaves, old leaves, flower buds, buds, young fruit and mature fruit. The expression of AT-SWEET16-1 gene in tissue was as follows: mature fruit>stem>root>flower bud>young fruit>old leaf>tender leaf. The expression of the gene in different fruit development stages was the highest in fruit stalk, relatively low in pulp and pericarp, and the lowest in seed, and the highest expression in fruit stalk and pulp was at fruit maturity stage. It was found that the gene was expressed in the phloem of the fruit stalk and between the cell membrane of the pulp cell wall, indicating that the gene played a role in the progress of the fruit development and the transport of plant nutrients.